The present disclosure relates to a check valve, and in particular, to an anti-flutter check valve for fluid management.
Check valves, such as those utilized in air management systems on aircraft, work automatically. One type of check valve includes a rotating member, such as a flap. When a threshold fluid velocity is reached, the flap begins to open. The flap includes ears with which the flap is mounted on a hinge pin, and a torsion spring is mounted on the hinge pin for flap closure. While the design of a check valve with a flap can be low weight and low cost, the flap is inherently unstable due to flutter. The closing torque on the spring increases proportionally with the opening angle of the flap while the projected area of the flap decreases. This results in the spring urging the flap to close, and results in oscillation, or flutter, of the flap between an open position and a closed position. Flutter can cause increased wear on the hinge pin or pulsations in an air management system that have adverse effects on the system's performance, including inconsistent flow and fluid velocity. Additionally, the torsion spring on the hinge pin typically has a limited length due to competing with the length of the flap ears on the hinge pin. The limited length limits the spring life, and flutter also limits the spring life due to continuous cyclic loading on the spring which can lead to spring failure. Moreover, flutter causes additional relative motion between the flap and the hinge pin resulting in detrimental wear on the pin, flap, or both.